forked from lijiext/lammps
50 lines
1.2 KiB
Plaintext
50 lines
1.2 KiB
Plaintext
"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
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:link(lws,http://lammps.sandia.gov)
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:link(ld,Manual.html)
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:link(lc,Section_commands.html#comm)
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:line
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angle_style cosine/shift command :h3
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[Syntax:]
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angle_style cosine/shift :pre
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[Examples:]
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angle_style cosine/shift
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angle_coeff * 10.0 45.0 :pre
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[Description:]
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The {cosine/shift} angle style uses the potential
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:c,image(Eqs/angle_cosine_shift.jpg)
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where theta0 is the equilibrium angle. The potential is bounded
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between -Umin and zero. In the neighborhood of the minimum E=- Umin +
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Umin/4(theta-theta0)^2 hence the spring constant is umin/2.
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The following coefficients must be defined for each angle type via the
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"angle_coeff"_angle_coeff.html command as in the example above, or in
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the data file or restart files read by the "read_data"_read_data.html
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or "read_restart"_read_restart.html commands:
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umin (energy)
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theta (angle) :ul
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[Restrictions:]
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This angle style can only be used if LAMMPS was built with the
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"user-misc" package. See the "Making LAMMPS"_Section_start.html#2_3
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section for more info on packages.
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[Related commands:]
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"angle_coeff"_angle_coeff.html,
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"angle_cosineshiftexp"_angle_cosineshiftexp.html
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[Default:] none
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